Hi @Sidathbb, welcome to the Cayenne Community!
It's all covered in that documentation, but specifically I would use 'Option 2' from the web dashboard install. Just login there and click the Raspberry Pi tile and follow the on screen instruction. You'll get to a page titled 'Connect your Raspberry Pi' where it will provide the 2 commands you need to type via SSH. They are custom to your account otherwise I'd share them here.
If you get stuck along the way just ask, we're happy to help.